Muffler with interlocked casing and baffle members



Nov. 30, 1965 c. E. NORDQUEST ETAL 3,

MUFFLER WITH INTERLOCKED CASING AND BAFFLE MEMBERS Filed Oct. 11,1961 4 Sheets-Sheet 1 Z4 INVENTORS Car) 4. Fordouesl 1?. mam 1'22 0. Ross BY w am?%' 7715 IR A ORA i) 3 1 c. E. NORDQUEST ETAL 3,220,508

MUFFLER WITH INTERLOCKED CASING AND BAFFLE MEMBERS Filed 00tll, 1961 4 Sheets-Sheet 2 DDDDD DDDDD DDDDD DDDDD DDDDD DDDDD DDDDD DDDDD DDDDD DDDD V- 3 1965 c. E. NORDQUEST EI'AL 3,

MUFFLER WITH INTERLOCKED CASING AND BAFFLE MEMBERS Filed Oct. 11, 1961 4 Sheets-Sheet 5 w INVENTORS Car) [2 para'auesz 46 %4 man/i2? 0. Ross /34 ZM I 3 1965 c. E. NORDQUEST ETAL 3,

MUFFLER WITH INTERLOCKED CASING AND BAFFLE MEMBERS Filed 001;. 11, 1961 4 Sheets-Sheet 4.

v Ky e sww M m r W A m k V n a w w a My 7 a United States Patent 3,220,508 MUFFLER WITH INTERLOCKED CASING AND BAFFLE MEMBERS Carl E. Nordquest and Marvin 0. Ross, Dayton, Ohio, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Oct. 11, 1961, Ser. No. 144,355 10 Claims. (Cl. 18161) This invention relates to mufilers and to the method of making mufflers for use on automobiles and the like.

It is an object of this invention to construct a muffler that the parts can be coated with porcelain and inspected for imperfections in the porcelain coating prior to final assembly.

A further object of this invention is to provide a basic mufiler design which makes it possible to utilize identical basic parts in constructing a large number of different mufilers capable of mufiling a wide range of noise frequencies.

Another object of this invention is to provide a mufiler construction in which parts of the muffler are coated with porcelain prior to final assembly and in which chipping of the porcelain within the muffler during final assembly is avoided.

Still another object of this invention is to provide a two-part muffler having a flanged joint in which the angle of the flange reduces the tendency for splitting open the seam in the event of a backfire.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a vertical sectional view taken substan tially on line 1-1 of FIGURE 2.

FIGURE 2 is a plan view of the bottom half of the muffler showing the sound attenuating baflles in place.

FIGURE 3 is a sectional view taken substantially on line 3-3 of FIGURE 2 showing the construction of the bottom portion of the muffler housing.

FIGURE 4 is a side elevational view showing one of the sound attenuating baffles.

FIGURE 5 is an end View of the same baflle.

FIGURE 6 is an enlarged fragmentary sectional view showing the details of construction of one of the tabs on the bafiles.

' FIGURE 7 is a fragmentary sectional view taken on line 7-7 of FIGURE 1.

FIGURE 8 is a plan view of the mufiler cover.

FIGURE 9 is a sectional view of the cover taken substantially on line 99 of FIGURE 8 showing the cover prior to its attachment to the mufiler housing.

Referring now to the drawings wherein a preferred embodiment of the invention has been shown, reference numeral 10 designates the bottom portion of a two part muffier housing. This bottom portion is in the form of a drawn shell element having a peripheral flange 12 which form an acute angle of approximately seventy-five degrees with the side wall of the drawn shell element 10. The open side 'of the drawn shell element 10 is closed by means of a cover element 14 having a flange portion 16 which is wrapped around the flange 12, as best shown in FIGURE 1 of the drawings. By virtue of this angular relationship, the tendency for the muffler to split open at the seam in case of a backfire is greatly reduced.

A plurality of baffles 20, 22, 24 and 26 are disposed within the, drawn shell element 10, as best shown in FIGURE 2 of the drawings. The number of baffles and the spacing of the baffles can be varied to meet the re- 7 Patented Nov. 30, 1965 quirements of any given engine exhaust system. The side walls of the drawn shell 10 are provided with a plurality of corrugations or guide slots 28 which serve to position the baffles. The edges of the bafiles are also spot welded to the sides and bottom of the shell element 10 so as to be held firmly in place. Since each muffier must be designed to match a given internal combustion engine and since minor changes in the design of an internal combustion engine materially effect the muffler construction required for properly muflling the noises generated by the engine, it is important to provide means for varying the construction and arrangement of the baffles within the main muffler housing without the need for making any major changes in the muffier. In the ar rangement shown in the drawings, the corrugations 28 serve as a convenient means for positioning the transversely extending baffles in any one of many different locations with the result that the same drawn shell can be used in conjunction with a large number of different engine designs. With this construction the same basic tools can be used in manufacturing a large number of different mufller designs;

Various muffler tubes 30, 32, 34 and 36 are disposed within the main muflier body and each of these tubes has its one end permanently secured to one of the transverse extending bafiles. Thus, tube 34, for example, has its one end secured to the baffle 24. The tube 30 has its one end secured to the baffle 20 and has its other end merely extending into a flange portion 38 formed on the baffle 22 but does not need to be secured to the baffle 22. The tube assembly 36 is permanently secured to one of the baffles, such as the baffle 24, and projects freely through openings in the other baffles through which it projects. By virtue of this arrangement, it is readily apparent that the locations of the baffles 20, 22, 24 and 26 can be varied considerably without changing the construction of these bafiles and without changing the construction of the drawn shell element 10. It is recognized that the length of the tubes 30, 32, 34 and 36 may have to be varied for different engine designs but this can be done without requiring any major tool changes.

As best shown in FIGURES 7 and 8, the cover element 14 is provided with a plurality of apertures 40 which are adapted to receive projecting tab elements 42 formed adjacent the one edge of each of the transversely extending baffles 20, 22, 24 and 26. FIGURES 4 and 6 show how the ends of the tab elements 42 are beveled at 44 and 46 so as to facilitate assembly of the cover 14 onto the tabs 42. Each tab is reduced in thickness by score lines as indicated at 47 whereby the tabs can be bent at this point without injury to the main porcelain coating which is applied to the mufller parts after the baffles have been secured in place but before the cover 14 is attached to the bottom shell or housing element 10.

It has been found desirable to porcelain coat all portions of the muffler which are exposed to the products of combustion. While it is recognized that it is old to use porcelain to coat the interior surfaces of a muffler, the big problem has been that of providing a satisfactory mufiier construction and enameling technique which will insure complete coating of all of the mufller parts. The complicated nature of the internal mufiler passages and chambers makes it very difficult, if not impossible, to properly coat the interior of the mufiier with porcelain after the muffler has been closed. It has been customary to pour the ingredients for the porcelain coating into the interior of a completely assembled muffler and to slosh it around in an attempt to coat all of the complex internal surfaces of the mufller but it has proven to be very difficult and impractical to completely cover all of the internal surfaces.

In applicants mufiier construction, the porcelain coating is applied to the bottom portion of the mufller housing after the baffles have been assembled therein but before the cover 14 is placed thereon. This not only makes it possible to better coat the interior surfaces of the element and the various baffles disposed therein but it also makes it possible to inspect the porcelain job before the cover 14 is assembled onto the drawn shell portion 10. The cover 14 is also coated with porcelain before it is fastened in place. After the parts have thus been coated with porcelain, the cover 14 is secured to the main housing element 10 by bending the tabs 42 along the score lines 47 and by bending the flange 16 of the cover around the flange 12 of the main housing or shell 10. Adjacent tabs are preferably bent in alternate directions. As best shown in FIGURE 7 of the drawings, a strip of asbestos 50 and a metal strip 52 are arranged over the row of perforations through which the tabs 42 project. The score lines 47 limit the area over which the porcelain coating is damaged when the tabs 42 are bent. Since these tabs 42 extend through the cover element 49, the asbestos strip 50 and the metal strip 52, it is obvious that no part of the associated battle which is located within the rnufller chamber has any damage done to the porcelain. Since that portion of the tabs which projects to the outside of the muffler housing are disposed on the top side of the muffler, they are largely protected from the elements which would tend to cause destructive rusting. In order to further protect the tabs from damage, a coating 54 of silicon powder and water glass is sprayed onto the top surface of the muifler.

The bottom surface of the muflier housing element 10 is protected from damage by gravel, etc., which might be thrown against the muffler by means of a stainless cover 64) which is provided with a flange construction 62 adjacent its upper edge which is wrapped around the flanged joint formed between the cover element 14 and the housing element It), as best shown in FIGURE 1 of the drawings. An intermediate layer of asbestos 63 is disposed between the housing element 10 and the stainless steel cover so as to insulate the cover 6t) from the housing element 10. Sealing compound 64 is provided at the edge of the flange 62 so as to prevent moisture from entering the space between the cover 60 and the housing element 10. This sealing compound can be any well known heat resistant sealing material, such as a silicon sealing compound.

While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A muflier for use with the exhaust system of an internal combustion engine including a shell construction having a first drawn shell element with side walls and a cover for said drawn shell element, said drawn shell element having a peripheral flange adjacent its open end, said flange being arranged at an acute angle relative to said side walls of said drawn shell element, said cover having a flange portion interlocking with said first named flange, a plurality of baflles disposed in said shell element in spaced relationship to one another, baflle positioning grooves formed in said side walls of said shell element for receiving and holding said bafiies in any one of a number of possible positions, means for securing said baflles to said drawn shell element, said cover having a plurality of apertures formed therein, said baffles having projections extending through said apertures and interlocking said cover and said baffles, a plurality of tubular members arranged in staggered relationship within said drawn shell element, each of said tubular members being secured to one of said baflles, certain of said tubular members extending through an aperture in a second of said baflles.

2. A muflier for use with the exhaust system of an internal combustion engine comprising in combination, a

dished out housing element with side walls, a cover for said housing element, said housing element having a peripheral flange adjacent its open side, said flange being arranged at an acute angle relative to said side walls of said housing element, said cover having a flange portion interlocking with said first named flange, a plurality of baflles disposed in said housing element in spaced relationship to one another, baflle positioning grooves formed in said side walls of said housing element for receiving and holding said battles in any one of a number of possible positions, means securing said baffles to said housing element, said cover having a plurality of apertures formed therein, said baffles having projections extending through said apertures and interlocking said cover and said baifles, a plurality of tubular baflle members arranged in staggered relationship within said housing element, each of said tubular members being secured to a baflie, certain of said tubular members extending through an aperture in a second of said baffles.

3. A mufiler for use with the exhaust system of an internal combustion engine including a shell construction having a first drawn shell element with side walls and a cover for said drawn shell element, said drawn shell element having a peripheral flange adjacent its open side, said flange being arranged at an acute angle relative to said side walls of said drawn shell element, said cover having a flange portion interlocking with said first named flange, a plurality of baflles disposed in said shell element in spaced relationship to one another, bafile positioning grooves formed in said side walls of said shell element for receiving and holding said bafiles in any one of a number of possible positions, means securing said batfles to said drawn shell element, said cover and said bafiles having interlocking parts thereon whereby said cover is held in assembled relationship relative to said drawn shell element and said baffles, a plurality of tubular members arranged in staggered relationship within said drawn shell element, each of said tubular members being secured to only one of said bafi'les, certain of said tubular members extending through an aperture in a second of said bafl les.

4-. A muflier for use with the exhaust system of an internal combustion engine including a shell construction having a first drawn shell element with side walls and a cover for said drawn shell element, said drawn shell element having a peripheral flange adjacent its open side, said flange being arranged at an acute angle relative to said side walls of said drawn shell element, said cover having a flange portion interlocking with said first named flange, a plurality of baflles disposed in said shell element in spaced relationship to one another, baflle positioning grooves formed in said side walls of said shell element for receiving and holding said baflles in any one of a number of possible positions, means securing said batfles to said drawn shell element, said cover having a plurality of apertures formed therein, said baflles having projections extending through said apertures and interlocking said cover and said baflies.

5. A mufller for use with the exhaust system of an internal combustion engine including a shell construction having a first recessed housing element with side walls and a cover for said element, a plurality of transversely extending baffles secured within said element in spaced relationship to one another, bafi'le positioning grooves formed in said side walls of said element for receiving and holding said baflles in position, a porcelain coating on said housing element and said baflles, said cover having a plurality of apertures formed therein, said baflles having projections extending through said apertures and bent over onto said cover, said projections having a reduced thickness along the line of bend so as to restrict damage to the porcelain to the line of bend.

6. A mufller including a shell construction having a first drawn shell element, a cover for said drawn shell element, a plurality of battles disposed in said shell element in spaced relationship to one another, means securing said bafiles to said drawn shell element, said shell element and said bafiles having a homogeneous porcelain coating thereon and said cover having a homogeneous porcelain coating thereon, said cover having a plurality of apertures formed therein, said baflles having projections extending through said apertures and interlocking said cover and said baflles.

7. A muffler for use with the exhaust system of an internal combustion engine comprising in combination a first drawn shell element with side walls, a cover for said drawn shell element, said drawn shell element having a peripheral flange arranged at an acute angle relative to said side walls of said drawn shell element, said cover having flange means interlocking with said first named flange, a plurality of baifles disposed in said shell element and secured thereto in spaced relationship to one another, baflles positioning grooves formed in said side walls of said shell element for receiving and positioning said batfles, said cover having a plurality of apertures formed therein, said baffles having projections extending through said apertures and interlocking said cover and said baflles, said drawn shell element and said baflles having a homogeneous porcelain coating thereon and said cover having a separate homogeneous porcelain coating thereon.

8. A mufller for use with the exhaust system of an internal combustion engine comprising in combination a first drawn shell element with side walls, a cover for said drawn shell element, said drawn shell element having a peripheral flange arranged at an acute angle relative to said side walls of said drawn shell element, said cover having flange means interlocking with said first named flange, a plurality of baflles disposed in said shell element and secured thereto in spaced relationship to one another, baffie positioning grooves formed in said side walls of said shell element for receiving and positioning said baflles, said cover having a plurality of apertures formed therein, said baflles having projections extending through said apertures and interlocking said cover and said baffles, said drawn shell element and said baflles having a homogeneous porcelain coating thereon and said cover having a separate homogeneous porcelain coating thereon, and means protecting the porcelain on the bottom side of said drawn shell element from foreign objects which might strike the bottom surface of said mufller.

9. A muffler for use with the exhaust system of an internal combustion engine comprising in combination a first drawn shell element with side walls, a cover for said drawn shell element, said drawn shell element having a peripheral flange arranged at an acute angle relative to said side walls of said drawn shell element, said cover having flange means interlocking with said first named flange, a plurality of baffles disposed in said shell element and secured thereto in spaced relationship to one another, bafile positioning grooves formed in said side walls of said shell element for receiving and positioning said baflies, said cover having a plurality of apertures formed therein, said bafl'les having projections extending through said apertures and interlocking said cover and said baifles, said drawn shell element and said batfles having a homogeneous porcelain coating thereon and said cover having a separate homogeneous porcelain coating thereon, and means protecting the porcelain on the bottom side of said drawn shell element from foreign objects which might strike the bottom surface of said muflder, said last named means comprising a stainless steel covering having its upper edge arranged to cover said flange means and a layer of asbestos between said stainless steel covering and said shell element.

10. A mufller for use with the exhaust system of an internal combustion engine including a shell construction having a first drawn shell element with side walls and a cover for said drawn shell element, a plurality of baflles disposed in said shell element in spaced relationship to one another, baflle positioning grooves formed in said side walls of said shell element for receiving and holding said baflles in any one of a number of possible positions, means securing said baflles to said drawn shell element, said cover and said baflles having interlocking parts thereon whereby said cover is held in assembled relationship relative to said drawn shell element.

References Cited by the Examiner UNITED STATES PATENTS 360,993 4/1887 Brown 29-458 689,797 12/1901 Erwin 29-458 1,353,863 9/1920 Taber 181-61 1,688,488 10/1928 Dormeyer 181-61 2,113,828 4/1928 Compo 181-61 2,326,283 8/ 1943 Bonsall 29-458 2,391,468 12/1945 Long 117-129 2,392,247 1/ 1946 Katcher. 2,395,005 2/1946 Kuhn 181-49 2,560,290 7/ 1951 Helberg 29-513 X 2,614,715 10/ 1952 Ross 220-22 2,703,635 3/ 1955 Carlson. 2,773,502 2/1956 Van Leer et a1 29-458 2,824,619 2/ 1958 Bremer et 211. 2,834,427 5/1958 Powers et al. 181-61 2,955,733 10/ 1960 Wilson 220-22 3,016,972 1/1962 Dugas 181-56 3,031,824 5/ 1962 Court. 3,082,841 3/1963 Powers 181-35.3

FOREIGN PATENTS 1,181,590 1/1959 France.

543,880 5/ 1956 Italy.

LEO SMILOW, Primary Examiner.

ALDRICH F. MEDBERY, Examiner. 

1. A MUFFLER FOR USE WITH THE EXHAUST SYSTEM OF AN INTERNAL COMBUSTION ENGINE INCLUDING A SHELL CONSTRUCTION HAVING A FIRST DRAWN SHELL ELEMENT WITH SIDE WALLS AND A COVER FOR SAID DRAWN SHELL ELEMENT, SAID DRAWN SHELL ELEMENT HAVING A PERIPHERAL FLANGE ADJACENT ITS OPEN END, SAID FLANGE BEING ARRANGED AT AN ACUTE ANGLE RELATIVE TO SAID SIDE WALLS OF SAID DRAWN SHELL ELEMENT, SAID COVER HAVING A FLANGE PORTION INTERLOCKING WITH SAID FIRST NAMED FLANGE, A PLURALITY OF BAFFLES DISPOSED IN SAID SHELL ELEMENT IN SPACED RELATIONSHIP TO ONE ANOTHER, BAFFLE POSITIONING GROOVES FORMED IN SAID SIDE WALLS OF SAID SHELL ELEMENT FOR RECEIVING AND HOLDING SAID BAFFLES IN ANY ONE OF A NUMBER OF POSSIBLE POSITIONS, MEANS FOR SECURING SAID BAFFLES 